/*
   Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/* Write a row to a MyISAM table */

#include "fulltext.h"
#include "rt_index.h"

#define MAX_POINTER_LENGTH 8

	/* Functions declared in this file */

static int w_search(MI_INFO *info,MI_KEYDEF *keyinfo,
		    uint comp_flag, uchar *key,
		    uint key_length, my_off_t pos, uchar *father_buff,
		    uchar *father_keypos, my_off_t father_page,
		    my_bool insert_last);
static int _mi_balance_page(MI_INFO *info,MI_KEYDEF *keyinfo,uchar *key,
			    uchar *curr_buff,uchar *father_buff,
			    uchar *father_keypos,my_off_t father_page);
static uchar *_mi_find_last_pos(MI_KEYDEF *keyinfo, uchar *page,
				uchar *key, uint *return_key_length,
				uchar **after_key);
int _mi_ck_write_tree(register MI_INFO *info, uint keynr,uchar *key,
		      uint key_length);
int _mi_ck_write_btree(register MI_INFO *info, uint keynr,uchar *key,
		       uint key_length);

	/* Write new record to database */

int mi_write(MI_INFO *info, uchar *record)
{
  MYISAM_SHARE *share=info->s;
  uint i;
  int save_errno;
  my_off_t filepos;
  uchar *buff;
  my_bool lock_tree= share->concurrent_insert;
  DBUG_ENTER("mi_write");
  DBUG_PRINT("enter",("isam: %d  data: %d",info->s->kfile,info->dfile));

  DBUG_EXECUTE_IF("myisam_pretend_crashed_table_on_usage",
                  mi_print_error(info->s, HA_ERR_CRASHED);
                  DBUG_RETURN(my_errno= HA_ERR_CRASHED););
  if (share->options & HA_OPTION_READ_ONLY_DATA)
  {
    DBUG_RETURN(my_errno=EACCES);
  }
  if (_mi_readinfo(info,F_WRLCK,1))
    DBUG_RETURN(my_errno);

  filepos= ((share->state.dellink != HA_OFFSET_ERROR &&
             !info->append_insert_at_end) ?
	    share->state.dellink :
	    info->state->data_file_length);

  if (share->base.reloc == (ha_rows) 1 &&
      share->base.records == (ha_rows) 1 &&
      info->state->records == (ha_rows) 1)
  {						/* System file */
    my_errno=HA_ERR_RECORD_FILE_FULL;
    goto err2;
  }
  if (info->state->key_file_length >= share->base.margin_key_file_length)
  {
    my_errno=HA_ERR_INDEX_FILE_FULL;
    goto err2;
  }
  if (_mi_mark_file_changed(info))
    goto err2;

  /* Calculate and check all unique constraints */
  if (mi_is_any_key_active(share->state.key_map))
  {
    for (i= 0 ; i < share->state.header.uniques ; i++)
    {
      if (mi_check_unique(info, share->uniqueinfo + i, record,
                          mi_unique_hash(share->uniqueinfo + i, record),
                          HA_OFFSET_ERROR))
        goto err2;
    }
  }

	/* Write all keys to indextree */

  buff=info->lastkey2;
  for (i=0 ; i < share->base.keys ; i++)
  {
    if (mi_is_key_active(share->state.key_map, i))
    {
      my_bool local_lock_tree= (lock_tree &&
                                !(info->bulk_insert &&
                                  is_tree_inited(&info->bulk_insert[i])));
      if (local_lock_tree)
      {
        mysql_rwlock_wrlock(&share->key_root_lock[i]);
	share->keyinfo[i].version++;
      }
      if (share->keyinfo[i].flag & HA_FULLTEXT )
      {
        if (_mi_ft_add(info,i, buff, record, filepos))
        {
	  if (local_lock_tree)
            mysql_rwlock_unlock(&share->key_root_lock[i]);
          DBUG_PRINT("error",("Got error: %d on write",my_errno));
          goto err;
        }
      }
      else
      {
        if (share->keyinfo[i].ck_insert(info,i,buff,
			_mi_make_key(info,i,buff,record,filepos)))
        {
          if (local_lock_tree)
            mysql_rwlock_unlock(&share->key_root_lock[i]);
          DBUG_PRINT("error",("Got error: %d on write",my_errno));
          goto err;
        }
      }

      /* The above changed info->lastkey2. Inform mi_rnext_same(). */
      info->update&= ~HA_STATE_RNEXT_SAME;

      if (local_lock_tree)
        mysql_rwlock_unlock(&share->key_root_lock[i]);
    }
  }
  if (share->calc_checksum)
    info->checksum=(*share->calc_checksum)(info,record);
  if (!(info->opt_flag & OPT_NO_ROWS))
  {
    if ((*share->write_record)(info,record))
      goto err;
    info->state->checksum+=info->checksum;
  }
  if (share->base.auto_key)
    set_if_bigger(info->s->state.auto_increment,
                  retrieve_auto_increment(info, record));
  info->update= (HA_STATE_CHANGED | HA_STATE_AKTIV | HA_STATE_WRITTEN |
		 HA_STATE_ROW_CHANGED);
  info->state->records++;
  info->lastpos=filepos;
  myisam_log_record(MI_LOG_WRITE,info,record,filepos,0);
  (void) _mi_writeinfo(info, WRITEINFO_UPDATE_KEYFILE);
  if (info->invalidator != 0)
  {
    DBUG_PRINT("info", ("invalidator... '%s' (update)", info->filename));
    (*info->invalidator)(info->filename);
    info->invalidator=0;
  }

  /*
    Update status of the table. We need to do so after each row write
    for the log tables, as we want the new row to become visible to
    other threads as soon as possible. We don't lock mutex here
    (as it is required by pthread memory visibility rules) as (1) it's
    not critical to use outdated share->is_log_table value (2) locking
    mutex here for every write is too expensive.
  */
  if (share->is_log_table)
    mi_update_status((void*) info);

  DBUG_RETURN(0);

err:
  save_errno=my_errno;
  if (my_errno == HA_ERR_FOUND_DUPP_KEY || my_errno == HA_ERR_RECORD_FILE_FULL ||
      my_errno == HA_ERR_NULL_IN_SPATIAL || my_errno == HA_ERR_OUT_OF_MEM)
  {
    if (info->bulk_insert)
    {
      uint j;
      for (j=0 ; j < share->base.keys ; j++)
        mi_flush_bulk_insert(info, j);
    }
    info->errkey= (int) i;
    while ( i-- > 0)
    {
      if (mi_is_key_active(share->state.key_map, i))
      {
	my_bool local_lock_tree= (lock_tree &&
                                  !(info->bulk_insert &&
                                    is_tree_inited(&info->bulk_insert[i])));
	if (local_lock_tree)
          mysql_rwlock_wrlock(&share->key_root_lock[i]);
	if (share->keyinfo[i].flag & HA_FULLTEXT)
        {
          if (_mi_ft_del(info,i, buff,record,filepos))
	  {
	    if (local_lock_tree)
              mysql_rwlock_unlock(&share->key_root_lock[i]);
            break;
	  }
        }
        else
	{
	  uint key_length=_mi_make_key(info,i,buff,record,filepos);
	  if (share->keyinfo[i].ck_delete(info, i, buff, key_length))
	  {
	    if (local_lock_tree)
              mysql_rwlock_unlock(&share->key_root_lock[i]);
	    break;
	  }
	}
	if (local_lock_tree)
          mysql_rwlock_unlock(&share->key_root_lock[i]);
      }
    }
  }
  else
  {
    mi_print_error(info->s, HA_ERR_CRASHED);
    mi_mark_crashed(info);
  }
  info->update= (HA_STATE_CHANGED | HA_STATE_WRITTEN | HA_STATE_ROW_CHANGED);
  my_errno=save_errno;
err2:
  save_errno=my_errno;
  myisam_log_record(MI_LOG_WRITE,info,record,filepos,my_errno);
  (void) _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
  DBUG_RETURN(my_errno=save_errno);
} /* mi_write */


	/* Write one key to btree */

int _mi_ck_write(MI_INFO *info, uint keynr, uchar *key, uint key_length)
{
  DBUG_ENTER("_mi_ck_write");

  if (info->bulk_insert && is_tree_inited(&info->bulk_insert[keynr]))
  {
    DBUG_RETURN(_mi_ck_write_tree(info, keynr, key, key_length));
  }
  else
  {
    DBUG_RETURN(_mi_ck_write_btree(info, keynr, key, key_length));
  }
} /* _mi_ck_write */


/**********************************************************************
 *                Normal insert code                                  *
 **********************************************************************/

int _mi_ck_write_btree(register MI_INFO *info, uint keynr, uchar *key,
		       uint key_length)
{
  int error;
  uint comp_flag;
  MI_KEYDEF *keyinfo=info->s->keyinfo+keynr;
  my_off_t  *root=&info->s->state.key_root[keynr];
  DBUG_ENTER("_mi_ck_write_btree");

  if (keyinfo->flag & HA_SORT_ALLOWS_SAME)
    comp_flag=SEARCH_BIGGER;			/* Put after same key */
  else if (keyinfo->flag & (HA_NOSAME|HA_FULLTEXT))
  {
    comp_flag=SEARCH_FIND | SEARCH_UPDATE;	/* No duplicates */
    if (keyinfo->flag & HA_NULL_ARE_EQUAL)
      comp_flag|= SEARCH_NULL_ARE_EQUAL;
  }
  else
    comp_flag=SEARCH_SAME;			/* Keys in rec-pos order */

  error=_mi_ck_real_write_btree(info, keyinfo, key, key_length,
                                root, comp_flag);
  if (info->ft1_to_ft2)
  {
    if (!error)
      error= _mi_ft_convert_to_ft2(info, keynr, key);
    delete_dynamic(info->ft1_to_ft2);
    my_free(info->ft1_to_ft2);
    info->ft1_to_ft2=0;
  }
  DBUG_RETURN(error);
} /* _mi_ck_write_btree */

int _mi_ck_real_write_btree(MI_INFO *info, MI_KEYDEF *keyinfo,
    uchar *key, uint key_length, my_off_t *root, uint comp_flag)
{
  int error;
  DBUG_ENTER("_mi_ck_real_write_btree");
  /* key_length parameter is used only if comp_flag is SEARCH_FIND */
  if (*root == HA_OFFSET_ERROR ||
      (error=w_search(info, keyinfo, comp_flag, key, key_length,
		      *root, (uchar *) 0, (uchar*) 0,
		      (my_off_t) 0, 1)) > 0)
    error=_mi_enlarge_root(info,keyinfo,key,root);
  DBUG_RETURN(error);
} /* _mi_ck_real_write_btree */


	/* Make a new root with key as only pointer */

int _mi_enlarge_root(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
                     my_off_t *root)
{
  uint t_length,nod_flag;
  MI_KEY_PARAM s_temp;
  MYISAM_SHARE *share=info->s;
  DBUG_ENTER("_mi_enlarge_root");

  nod_flag= (*root != HA_OFFSET_ERROR) ?  share->base.key_reflength : 0;
  _mi_kpointer(info,info->buff+2,*root); /* if nod */
  t_length=(*keyinfo->pack_key)(keyinfo,nod_flag,(uchar*) 0,
				(uchar*) 0, (uchar*) 0, key,&s_temp);
  mi_putint(info->buff,t_length+2+nod_flag,nod_flag);
  (*keyinfo->store_key)(keyinfo,info->buff+2+nod_flag,&s_temp);
  info->buff_used=info->page_changed=1;		/* info->buff is used */
  if ((*root= _mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR ||
      _mi_write_keypage(info,keyinfo,*root,DFLT_INIT_HITS,info->buff))
    DBUG_RETURN(-1);
  DBUG_RETURN(0);
} /* _mi_enlarge_root */


	/*
	  Search after a position for a key and store it there
	  Returns -1 = error
		   0  = ok
		   1  = key should be stored in higher tree
	*/

static int w_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
		    uint comp_flag, uchar *key, uint key_length, my_off_t page,
		    uchar *father_buff, uchar *father_keypos,
		    my_off_t father_page, my_bool insert_last)
{
  int error,flag;
  uint nod_flag, search_key_length;
  uchar *temp_buff,*keypos;
  uchar keybuff[MI_MAX_KEY_BUFF];
  my_bool was_last_key;
  my_off_t next_page, dupp_key_pos;
  DBUG_ENTER("w_search");
  DBUG_PRINT("enter",("page: %ld", (long) page));

  search_key_length= (comp_flag & SEARCH_FIND) ? key_length : USE_WHOLE_KEY;
  if (!(temp_buff= (uchar*) my_alloca((uint) keyinfo->block_length+
				      MI_MAX_KEY_BUFF*2)))
    DBUG_RETURN(-1);
  if (!_mi_fetch_keypage(info,keyinfo,page,DFLT_INIT_HITS,temp_buff,0))
    goto err;

  flag=(*keyinfo->bin_search)(info,keyinfo,temp_buff,key,search_key_length,
			      comp_flag, &keypos, keybuff, &was_last_key);
  nod_flag=mi_test_if_nod(temp_buff);
  if (flag == 0)
  {
    uint tmp_key_length;
	/* get position to record with duplicated key */
    tmp_key_length=(*keyinfo->get_key)(keyinfo,nod_flag,&keypos,keybuff);
    if (tmp_key_length)
      dupp_key_pos=_mi_dpos(info,0,keybuff+tmp_key_length);
    else
      dupp_key_pos= HA_OFFSET_ERROR;

    if (keyinfo->flag & HA_FULLTEXT)
    {
      uint off;
      int  subkeys;

      get_key_full_length_rdonly(off, keybuff);
      subkeys=ft_sintXkorr(keybuff+off);
      comp_flag=SEARCH_SAME;
      if (subkeys >= 0)
      {
        /* normal word, one-level tree structure */
        flag=(*keyinfo->bin_search)(info, keyinfo, temp_buff, key,
                                    USE_WHOLE_KEY, comp_flag,
                                    &keypos, keybuff, &was_last_key);
      }
      else
      {
        /* popular word. two-level tree. going down */
        my_off_t root=dupp_key_pos;
        keyinfo=&info->s->ft2_keyinfo;
        get_key_full_length_rdonly(off, key);
        key+=off;
        keypos-=keyinfo->keylength+nod_flag; /* we'll modify key entry 'in vivo' */
        error=_mi_ck_real_write_btree(info, keyinfo, key, 0,
                                      &root, comp_flag);
        _mi_dpointer(info, keypos+HA_FT_WLEN, root);
        subkeys--; /* should there be underflow protection ? */
        DBUG_ASSERT(subkeys < 0);
        ft_intXstore(keypos, subkeys);
        if (!error)
          error=_mi_write_keypage(info,keyinfo,page,DFLT_INIT_HITS,temp_buff);
        my_afree((uchar*) temp_buff);
        DBUG_RETURN(error);
      }
    }
    else /* not HA_FULLTEXT, normal HA_NOSAME key */
    {
      info->dupp_key_pos= dupp_key_pos;
      my_afree((uchar*) temp_buff);
      my_errno=HA_ERR_FOUND_DUPP_KEY;
      DBUG_RETURN(-1);
    }
  }
  if (flag == MI_FOUND_WRONG_KEY)
    DBUG_RETURN(-1);
  if (!was_last_key)
    insert_last=0;
  next_page=_mi_kpos(nod_flag,keypos);
  if (next_page == HA_OFFSET_ERROR ||
      (error=w_search(info, keyinfo, comp_flag, key, key_length, next_page,
		      temp_buff, keypos, page, insert_last)) >0)
  {
    error=_mi_insert(info,keyinfo,key,temp_buff,keypos,keybuff,father_buff,
		     father_keypos,father_page, insert_last);
    if (_mi_write_keypage(info,keyinfo,page,DFLT_INIT_HITS,temp_buff))
      goto err;
  }
  my_afree((uchar*) temp_buff);
  DBUG_RETURN(error);
err:
  my_afree((uchar*) temp_buff);
  DBUG_PRINT("exit",("Error: %d",my_errno));
  DBUG_RETURN (-1);
} /* w_search */


/*
  Insert new key.

  SYNOPSIS
    _mi_insert()
    info                        Open table information.
    keyinfo                     Key definition information.
    key                         New key.
    anc_buff                    Key page (beginning).
    key_pos                     Position in key page where to insert.
    key_buff                    Copy of previous key.
    father_buff                 parent key page for balancing.
    father_key_pos              position in parent key page for balancing.
    father_page                 position of parent key page in file.
    insert_last                 If to append at end of page.

  DESCRIPTION
    Insert new key at right of key_pos.

  RETURN
    2           if key contains key to upper level.
    0           OK.
    < 0         Error.
*/

int _mi_insert(register MI_INFO *info, register MI_KEYDEF *keyinfo,
	       uchar *key, uchar *anc_buff, uchar *key_pos, uchar *key_buff,
               uchar *father_buff, uchar *father_key_pos, my_off_t father_page,
	       my_bool insert_last)
{
  uint a_length,nod_flag;
  int t_length;
  uchar *endpos, *prev_key;
  MI_KEY_PARAM s_temp;
  DBUG_ENTER("_mi_insert");
  DBUG_PRINT("enter",("key_pos: 0x%lx", (long) key_pos));
  DBUG_EXECUTE("key",_mi_print_key(DBUG_FILE,keyinfo->seg,key,USE_WHOLE_KEY););

  nod_flag=mi_test_if_nod(anc_buff);
  a_length=mi_getint(anc_buff);
  endpos= anc_buff+ a_length;
  prev_key=(key_pos == anc_buff+2+nod_flag ? (uchar*) 0 : key_buff);
  t_length=(*keyinfo->pack_key)(keyinfo,nod_flag,
				(key_pos == endpos ? (uchar*) 0 : key_pos),
				prev_key, prev_key,
				key,&s_temp);
#ifndef DBUG_OFF
  if (key_pos != anc_buff+2+nod_flag && (keyinfo->flag &
					 (HA_BINARY_PACK_KEY | HA_PACK_KEY)))
  {
    DBUG_DUMP("prev_key",(uchar*) key_buff,_mi_keylength(keyinfo,key_buff));
  }
  if (keyinfo->flag & HA_PACK_KEY)
  {
    DBUG_PRINT("test",("t_length: %d  ref_len: %d",
		       t_length,s_temp.ref_length));
    DBUG_PRINT("test",("n_ref_len: %d  n_length: %d  key_pos: 0x%lx",
		       s_temp.n_ref_length,s_temp.n_length, (long) s_temp.key));
  }
#endif
  if (t_length > 0)
  {
    if (t_length >= keyinfo->maxlength*2+MAX_POINTER_LENGTH)
    {
      mi_print_error(info->s, HA_ERR_CRASHED);
      my_errno=HA_ERR_CRASHED;
      DBUG_RETURN(-1);
    }
    bmove_upp((uchar*) endpos+t_length,(uchar*) endpos,(uint) (endpos-key_pos));
  }
  else
  {
    if (-t_length >= keyinfo->maxlength*2+MAX_POINTER_LENGTH)
    {
      mi_print_error(info->s, HA_ERR_CRASHED);
      my_errno=HA_ERR_CRASHED;
      DBUG_RETURN(-1);
    }
    bmove(key_pos,key_pos-t_length,(uint) (endpos-key_pos)+t_length);
  }
  (*keyinfo->store_key)(keyinfo,key_pos,&s_temp);
  a_length+=t_length;
  mi_putint(anc_buff,a_length,nod_flag);
  if (a_length <= keyinfo->block_length)
  {
    if (keyinfo->block_length - a_length < 32 &&
        keyinfo->flag & HA_FULLTEXT && key_pos == endpos &&
        info->s->base.key_reflength <= info->s->rec_reflength &&
        info->s->options & (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD))
    {
      /*
        Normal word. One-level tree. Page is almost full.
        Let's consider converting.
        We'll compare 'key' and the first key at anc_buff
       */
      uchar *a=key, *b=anc_buff+2+nod_flag;
      uint alen, blen, ft2len=info->s->ft2_keyinfo.keylength;
      /* the very first key on the page is always unpacked */
      DBUG_ASSERT((*b & 128) == 0);
#if HA_FT_MAXLEN >= 127
      blen= mi_uint2korr(b); b+=2;
#else
      blen= *b++;
#endif
      get_key_length(alen,a);
      DBUG_ASSERT(info->ft1_to_ft2==0);
      if (alen == blen &&
          ha_compare_text(keyinfo->seg->charset, a, alen, b, blen, 0, 0)==0)
      {
        /* yup. converting */
        info->ft1_to_ft2=(DYNAMIC_ARRAY *)
          my_malloc(sizeof(DYNAMIC_ARRAY), MYF(MY_WME));
        my_init_dynamic_array(info->ft1_to_ft2, ft2len, 300, 50);

        /*
          now, adding all keys from the page to dynarray
          if the page is a leaf (if not keys will be deleted later)
        */
        if (!nod_flag)
        {
          /* let's leave the first key on the page, though, because
             we cannot easily dispatch an empty page here */
          b+=blen+ft2len+2;
          for (a=anc_buff+a_length ; b < a ; b+=ft2len+2)
          {
            if (insert_dynamic(info->ft1_to_ft2, b))
            {
              mi_print_error(info->s, HA_ERR_OUT_OF_MEM);
              my_errno= HA_ERR_OUT_OF_MEM;
              DBUG_RETURN(-1);
            }
          }

          /* fixing the page's length - it contains only one key now */
          mi_putint(anc_buff,2+blen+ft2len+2,0);
        }
        /* the rest will be done when we're back from recursion */
      }
    }
    DBUG_RETURN(0);				/* There is room on page */
  }
  /* Page is full */
  if (nod_flag)
    insert_last=0;
  if (!(keyinfo->flag & (HA_VAR_LENGTH_KEY | HA_BINARY_PACK_KEY)) &&
      father_buff && !insert_last)
    DBUG_RETURN(_mi_balance_page(info,keyinfo,key,anc_buff,father_buff,
				 father_key_pos,father_page));
  DBUG_RETURN(_mi_split_page(info,keyinfo,key,anc_buff,key_buff, insert_last));
} /* _mi_insert */


	/* split a full page in two and assign emerging item to key */

int _mi_split_page(register MI_INFO *info, register MI_KEYDEF *keyinfo,
		   uchar *key, uchar *buff, uchar *key_buff,
		   my_bool insert_last_key)
{
  uint length,a_length,key_ref_length,t_length,nod_flag,key_length;
  uchar *key_pos,*pos, *after_key;
  my_off_t new_pos;
  MI_KEY_PARAM s_temp;
  DBUG_ENTER("mi_split_page");
  LINT_INIT(after_key);
  DBUG_DUMP("buff",(uchar*) buff,mi_getint(buff));

  if (info->s->keyinfo+info->lastinx == keyinfo)
    info->page_changed=1;			/* Info->buff is used */
  info->buff_used=1;
  nod_flag=mi_test_if_nod(buff);
  key_ref_length=2+nod_flag;
  if (insert_last_key)
    key_pos=_mi_find_last_pos(keyinfo,buff,key_buff, &key_length, &after_key);
  else
    key_pos=_mi_find_half_pos(nod_flag,keyinfo,buff,key_buff, &key_length,
			      &after_key);
  if (!key_pos)
    DBUG_RETURN(-1);

  length=(uint) (key_pos-buff);
  a_length=mi_getint(buff);
  mi_putint(buff,length,nod_flag);

  key_pos=after_key;
  if (nod_flag)
  {
    DBUG_PRINT("test",("Splitting nod"));
    pos=key_pos-nod_flag;
    memcpy((uchar*) info->buff+2,(uchar*) pos,(size_t) nod_flag);
  }

	/* Move middle item to key and pointer to new page */
  if ((new_pos=_mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
    DBUG_RETURN(-1);
  _mi_kpointer(info,_mi_move_key(keyinfo,key,key_buff),new_pos);

	/* Store new page */
  if (!(*keyinfo->get_key)(keyinfo,nod_flag,&key_pos,key_buff))
    DBUG_RETURN(-1);

  t_length=(*keyinfo->pack_key)(keyinfo,nod_flag,(uchar *) 0,
				(uchar*) 0, (uchar*) 0,
				key_buff, &s_temp);
  length=(uint) ((buff+a_length)-key_pos);
  memcpy((uchar*) info->buff+key_ref_length+t_length,(uchar*) key_pos,
	 (size_t) length);
  (*keyinfo->store_key)(keyinfo,info->buff+key_ref_length,&s_temp);
  mi_putint(info->buff,length+t_length+key_ref_length,nod_flag);

  if (_mi_write_keypage(info,keyinfo,new_pos,DFLT_INIT_HITS,info->buff))
    DBUG_RETURN(-1);
  DBUG_DUMP("key",(uchar*) key,_mi_keylength(keyinfo,key));
  DBUG_RETURN(2);				/* Middle key up */
} /* _mi_split_page */


	/*
	  Calculate how to much to move to split a page in two
	  Returns pointer to start of key.
	  key will contain the key.
	  return_key_length will contain the length of key
	  after_key will contain the position to where the next key starts
	*/

uchar *_mi_find_half_pos(uint nod_flag, MI_KEYDEF *keyinfo, uchar *page,
			 uchar *key, uint *return_key_length,
			 uchar **after_key)
{
  uint keys,length,key_ref_length;
  uchar *end,*lastpos;
  DBUG_ENTER("_mi_find_half_pos");

  key_ref_length=2+nod_flag;
  length=mi_getint(page)-key_ref_length;
  page+=key_ref_length;
  if (!(keyinfo->flag &
	(HA_PACK_KEY | HA_SPACE_PACK_USED | HA_VAR_LENGTH_KEY |
	 HA_BINARY_PACK_KEY)))
  {
    key_ref_length=keyinfo->keylength+nod_flag;
    keys=length/(key_ref_length*2);
    *return_key_length=keyinfo->keylength;
    end=page+keys*key_ref_length;
    *after_key=end+key_ref_length;
    memcpy(key,end,key_ref_length);
    DBUG_RETURN(end);
  }

  end=page+length/2-key_ref_length;		/* This is aprox. half */
  *key='\0';
  do
  {
    lastpos=page;
    if (!(length=(*keyinfo->get_key)(keyinfo,nod_flag,&page,key)))
      DBUG_RETURN(0);
  } while (page < end);
  *return_key_length=length;
  *after_key=page;
  DBUG_PRINT("exit",("returns: 0x%lx  page: 0x%lx  half: 0x%lx",
                     (long) lastpos, (long) page, (long) end));
  DBUG_RETURN(lastpos);
} /* _mi_find_half_pos */


	/*
	  Split buffer at last key
	  Returns pointer to the start of the key before the last key
	  key will contain the last key
	*/

static uchar *_mi_find_last_pos(MI_KEYDEF *keyinfo, uchar *page,
				uchar *key, uint *return_key_length,
				uchar **after_key)
{
  uint keys,length,UNINIT_VAR(last_length),key_ref_length;
  uchar *end,*lastpos,*UNINIT_VAR(prevpos);
  uchar key_buff[MI_MAX_KEY_BUFF];
  DBUG_ENTER("_mi_find_last_pos");

  key_ref_length=2;
  length=mi_getint(page)-key_ref_length;
  page+=key_ref_length;
  if (!(keyinfo->flag &
	(HA_PACK_KEY | HA_SPACE_PACK_USED | HA_VAR_LENGTH_KEY |
	 HA_BINARY_PACK_KEY)))
  {
    keys=length/keyinfo->keylength-2;
    *return_key_length=length=keyinfo->keylength;
    end=page+keys*length;
    *after_key=end+length;
    memcpy(key,end,length);
    DBUG_RETURN(end);
  }

  end=page+length-key_ref_length;
  *key='\0';
  length=0;
  lastpos=page;
  while (page < end)
  {
    prevpos=lastpos; lastpos=page;
    last_length=length;
    memcpy(key, key_buff, length);		/* previous key */
    if (!(length=(*keyinfo->get_key)(keyinfo,0,&page,key_buff)))
    {
      mi_print_error(keyinfo->share, HA_ERR_CRASHED);
      my_errno=HA_ERR_CRASHED;
      DBUG_RETURN(0);
    }
  }
  *return_key_length=last_length;
  *after_key=lastpos;
  DBUG_PRINT("exit",("returns: 0x%lx  page: 0x%lx  end: 0x%lx",
                     (long) prevpos,(long) page,(long) end));
  DBUG_RETURN(prevpos);
} /* _mi_find_last_pos */


	/* Balance page with not packed keys with page on right/left */
	/* returns 0 if balance was done */

static int _mi_balance_page(register MI_INFO *info, MI_KEYDEF *keyinfo,
			    uchar *key, uchar *curr_buff, uchar *father_buff,
			    uchar *father_key_pos, my_off_t father_page)
{
  my_bool right;
  uint k_length,father_length,father_keylength,nod_flag,curr_keylength,
       right_length,left_length,new_right_length,new_left_length,extra_length,
       length,keys;
  uchar *pos,*buff,*extra_buff;
  my_off_t next_page,new_pos;
  uchar tmp_part_key[MI_MAX_KEY_BUFF];
  DBUG_ENTER("_mi_balance_page");

  k_length=keyinfo->keylength;
  father_length=mi_getint(father_buff);
  father_keylength=k_length+info->s->base.key_reflength;
  nod_flag=mi_test_if_nod(curr_buff);
  curr_keylength=k_length+nod_flag;
  info->page_changed=1;

  if ((father_key_pos != father_buff+father_length &&
       (info->state->records & 1)) ||
      father_key_pos == father_buff+2+info->s->base.key_reflength)
  {
    right=1;
    next_page= _mi_kpos(info->s->base.key_reflength,
			father_key_pos+father_keylength);
    buff=info->buff;
    DBUG_PRINT("test",("use right page: %lu", (ulong) next_page));
  }
  else
  {
    right=0;
    father_key_pos-=father_keylength;
    next_page= _mi_kpos(info->s->base.key_reflength,father_key_pos);
					/* Fix that curr_buff is to left */
    buff=curr_buff; curr_buff=info->buff;
    DBUG_PRINT("test",("use left page: %lu", (ulong) next_page));
  }					/* father_key_pos ptr to parting key */

  if (!_mi_fetch_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,info->buff,0))
    goto err;
  DBUG_DUMP("next",(uchar*) info->buff,mi_getint(info->buff));

	/* Test if there is room to share keys */

  left_length=mi_getint(curr_buff);
  right_length=mi_getint(buff);
  keys=(left_length+right_length-4-nod_flag*2)/curr_keylength;

  if ((right ? right_length : left_length) + curr_keylength <=
      keyinfo->block_length)
  {						/* Merge buffs */
    new_left_length=2+nod_flag+(keys/2)*curr_keylength;
    new_right_length=2+nod_flag+((keys+1)/2)*curr_keylength;
    mi_putint(curr_buff,new_left_length,nod_flag);
    mi_putint(buff,new_right_length,nod_flag);

    if (left_length < new_left_length)
    {						/* Move keys buff -> leaf */
      pos=curr_buff+left_length;
      memcpy((uchar*) pos,(uchar*) father_key_pos, (size_t) k_length);
      memcpy((uchar*) pos+k_length, (uchar*) buff+2,
	     (size_t) (length=new_left_length - left_length - k_length));
      pos=buff+2+length;
      memcpy((uchar*) father_key_pos,(uchar*) pos,(size_t) k_length);
      bmove((uchar*) buff + 2, (uchar*) pos + k_length, new_right_length - 2);
    }
    else
    {						/* Move keys -> buff */

      bmove_upp((uchar*) buff+new_right_length,(uchar*) buff+right_length,
		right_length-2);
      length=new_right_length-right_length-k_length;
      memcpy((uchar*) buff+2+length,father_key_pos,(size_t) k_length);
      pos=curr_buff+new_left_length;
      memcpy((uchar*) father_key_pos,(uchar*) pos,(size_t) k_length);
      memcpy((uchar*) buff+2,(uchar*) pos+k_length,(size_t) length);
    }

    if (_mi_write_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,info->buff) ||
	_mi_write_keypage(info,keyinfo,father_page,DFLT_INIT_HITS,father_buff))
      goto err;
    DBUG_RETURN(0);
  }

	/* curr_buff[] and buff[] are full, lets split and make new nod */

  extra_buff=info->buff+info->s->base.max_key_block_length;
  new_left_length=new_right_length=2+nod_flag+(keys+1)/3*curr_keylength;
  if (keys == 5)				/* Too few keys to balance */
    new_left_length-=curr_keylength;
  extra_length=nod_flag+left_length+right_length-
    new_left_length-new_right_length-curr_keylength;
  DBUG_PRINT("info",("left_length: %d  right_length: %d  new_left_length: %d  new_right_length: %d  extra_length: %d",
		     left_length, right_length,
		     new_left_length, new_right_length,
		     extra_length));
  mi_putint(curr_buff,new_left_length,nod_flag);
  mi_putint(buff,new_right_length,nod_flag);
  mi_putint(extra_buff,extra_length+2,nod_flag);

  /* move first largest keys to new page  */
  pos=buff+right_length-extra_length;
  memcpy((uchar*) extra_buff+2,pos,(size_t) extra_length);
  /* Save new parting key */
  memcpy(tmp_part_key, pos-k_length,k_length);
  /* Make place for new keys */
  bmove_upp((uchar*) buff+new_right_length,(uchar*) pos-k_length,
	    right_length-extra_length-k_length-2);
  /* Copy keys from left page */
  pos= curr_buff+new_left_length;
  memcpy((uchar*) buff+2,(uchar*) pos+k_length,
	 (size_t) (length=left_length-new_left_length-k_length));
  /* Copy old parting key */
  memcpy((uchar*) buff+2+length,father_key_pos,(size_t) k_length);

  /* Move new parting keys up to caller */
  memcpy((uchar*) (right ? key : father_key_pos),pos,(size_t) k_length);
  memcpy((uchar*) (right ? father_key_pos : key),tmp_part_key, k_length);

  if ((new_pos=_mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
    goto err;
  _mi_kpointer(info,key+k_length,new_pos);
  if (_mi_write_keypage(info,keyinfo,(right ? new_pos : next_page),
			DFLT_INIT_HITS,info->buff) ||
      _mi_write_keypage(info,keyinfo,(right ? next_page : new_pos),
                        DFLT_INIT_HITS,extra_buff))
    goto err;

  DBUG_RETURN(1);				/* Middle key up */

err:
  DBUG_RETURN(-1);
} /* _mi_balance_page */

/**********************************************************************
 *                Bulk insert code                                    *
 **********************************************************************/

typedef struct {
  MI_INFO *info;
  uint keynr;
} bulk_insert_param;

int _mi_ck_write_tree(register MI_INFO *info, uint keynr, uchar *key,
		      uint key_length)
{
  int error;
  DBUG_ENTER("_mi_ck_write_tree");

  error= tree_insert(&info->bulk_insert[keynr], key,
         key_length + info->s->rec_reflength,
         info->bulk_insert[keynr].custom_arg) ? 0 : HA_ERR_OUT_OF_MEM ;

  DBUG_RETURN(error);
} /* _mi_ck_write_tree */


/* typeof(_mi_keys_compare)=qsort_cmp2 */

static int keys_compare(bulk_insert_param *param, uchar *key1, uchar *key2)
{
  uint not_used[2];
  return ha_key_cmp(param->info->s->keyinfo[param->keynr].seg,
                    key1, key2, USE_WHOLE_KEY, SEARCH_SAME,
                    not_used);
}


static int keys_free(uchar *key, TREE_FREE mode, bulk_insert_param *param)
{
  /*
    Probably I can use info->lastkey here, but I'm not sure,
    and to be safe I'd better use local lastkey.
  */
  uchar lastkey[MI_MAX_KEY_BUFF];
  uint keylen;
  MI_KEYDEF *keyinfo;

  switch (mode) {
  case free_init:
    if (param->info->s->concurrent_insert)
    {
      mysql_rwlock_wrlock(&param->info->s->key_root_lock[param->keynr]);
      param->info->s->keyinfo[param->keynr].version++;
    }
    return 0;
  case free_free:
    keyinfo=param->info->s->keyinfo+param->keynr;
    keylen=_mi_keylength(keyinfo, key);
    memcpy(lastkey, key, keylen);
    return _mi_ck_write_btree(param->info,param->keynr,lastkey,
			      keylen - param->info->s->rec_reflength);
  case free_end:
    if (param->info->s->concurrent_insert)
      mysql_rwlock_unlock(&param->info->s->key_root_lock[param->keynr]);
    return 0;
  }
  return -1;
}


int mi_init_bulk_insert(MI_INFO *info, ulong cache_size, ha_rows rows)
{
  MYISAM_SHARE *share=info->s;
  MI_KEYDEF *key=share->keyinfo;
  bulk_insert_param *params;
  uint i, num_keys, total_keylength;
  ulonglong key_map;
  DBUG_ENTER("_mi_init_bulk_insert");
  DBUG_PRINT("enter",("cache_size: %lu", cache_size));

  DBUG_ASSERT(!info->bulk_insert &&
	      (!rows || rows >= MI_MIN_ROWS_TO_USE_BULK_INSERT));

  mi_clear_all_keys_active(key_map);
  for (i=total_keylength=num_keys=0 ; i < share->base.keys ; i++)
  {
    if (! (key[i].flag & HA_NOSAME) && (share->base.auto_key != i + 1) &&
        mi_is_key_active(share->state.key_map, i))
    {
      num_keys++;
      mi_set_key_active(key_map, i);
      total_keylength+=key[i].maxlength+TREE_ELEMENT_EXTRA_SIZE;
    }
  }

  if (num_keys==0 ||
      num_keys * MI_MIN_SIZE_BULK_INSERT_TREE > cache_size)
    DBUG_RETURN(0);

  if (rows && rows*total_keylength < cache_size)
    cache_size= (ulong)rows;
  else
    cache_size/=total_keylength*16;

  info->bulk_insert=(TREE *)
    my_malloc((sizeof(TREE)*share->base.keys+
               sizeof(bulk_insert_param)*num_keys),MYF(0));

  if (!info->bulk_insert)
    DBUG_RETURN(HA_ERR_OUT_OF_MEM);

  params=(bulk_insert_param *)(info->bulk_insert+share->base.keys);
  for (i=0 ; i < share->base.keys ; i++)
  {
    if (mi_is_key_active(key_map, i))
    {
      params->info=info;
      params->keynr=i;
      /* Only allocate a 16'th of the buffer at a time */
      init_tree(&info->bulk_insert[i],
                cache_size * key[i].maxlength,
                cache_size * key[i].maxlength, 0,
		(qsort_cmp2)keys_compare, 0,
		(tree_element_free) keys_free, (void *)params++);
    }
    else
     info->bulk_insert[i].root=0;
  }

  DBUG_RETURN(0);
}

void mi_flush_bulk_insert(MI_INFO *info, uint inx)
{
  if (info->bulk_insert)
  {
    if (is_tree_inited(&info->bulk_insert[inx]))
      reset_tree(&info->bulk_insert[inx]);
  }
}

void mi_end_bulk_insert(MI_INFO *info)
{
  if (info->bulk_insert)
  {
    uint i;
    for (i=0 ; i < info->s->base.keys ; i++)
    {
      if (is_tree_inited(& info->bulk_insert[i]))
      {
        delete_tree(& info->bulk_insert[i]);
      }
    }
    my_free(info->bulk_insert);
    info->bulk_insert=0;
  }
}
